A glow-in-the-dark virus maps a gut-brain link

With the help of a glow-in-the-dark rabies virus, scientists have discovered a possible new signaling pathway between the gut and the brain in mice. Researchers previously discovered sensory cells lining the gut had nerve endings. In new research, scientists set out to map that connection by putting a fluorescent virus into the stomachs of mice and watching it travel to the vagus nerve and then the brain stem. They also grew sensory gut cells with vagal neurons, which fired signals when the two connected. That suggests a neurotransmitter like glutamate might be ferrying messages between the gut and the brain.